Device for testing corrugated paper-board and corrugated-paper-board boxes



I. W. WEBB. DEVICE FOR TESTING CORRUGATED PAPER BOARD AND CORRUGATED PAPER BOARD BOXES.

APPLICATION FILED OCT. l0, 1918.

Patented Ja11. 20, 1920.

Mace.

JAL.

-nEvIoE ron TESTING CORRUGATED.

` .UNITED STATES PATENT oFF-ICE.

JOHN W. WEBB, OF CHICAGO, ILLINOIS, SSIGNOR, BY MESNE ASSIGNMENTS, T0 WEBB` TESTER INCORPORATED, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

...To all whom/it ma concern Be it known t at I, JOHN W. WEBB, a

i citizen of the United States, residing atChip cago, -in the county of Cook and State of Illinois, have invented certain new and useful Improvements in vDevices for Testing Corrugated Paper-Board and Corrugated- Paper-Board Boxes', of which the; following is a specioation.-

The corrugated paper board and corru-" gated paperboard box testing device which constitutes my present invention is intended and designed'to provide a simple, compact and reliable 'pocket instrument by means of which the facings of corrugated paper articles may be tested to ascertain whethersuoh facings meetA specified requirements as to their strength. In recent years what is commercially termed double-faced corrugated straw board (the corrugated member usually being made of straw paper) has come into extensive use for the manufacture -of various sorts of cartons and packing boxes designed for the shipment of articles by railway and other transportation comin view, and with the object of providing a suitable and efficient instrument forthe purposes in view, I have invented and designed the device hereinafter more partie ularly described, -the essential elements of my inventionbeing more-particularly pointed out in the appended claims.

Figure-1 of the drawing is a side elevation of my novel testing device; Fig. 2 a central longitudinal section of the sameon a larger scale than Fig. 1; Fig. 3 is a bottomA plan view; Fig. 4 is a section on the line l portion of the barrel 1.

PAPER-'BOARD AND oonnUGATED-PAPEn-BOARD BoxEs.

Specification of Letters Patent. Patented Jan, 20, 19%, i 'Application ined october 1o, 191s. Aserial No. 257,5e3f

tails showing respectively a bottom plan view, a side elevation (partly in section) and a second sideelevation at right angles to the first, mentioned side elevation, of a modified formof plunger tip.

. The same reference characters indicate the same parts in all the figures of the drawing.

The specific construction of the device yas illustrated in the drawing will now be described. To the lower end of the tubular barrel forming the shank ofthe tester is secured (in the present instance by means lof a screw-threaded engagement) a slotted finger block 2,.the lower. or outer part ofthe block consisting of a finger 2 having la flat upper face and a rounded lower face shaped to'enter and fit the space between the upper facing of a piece of corrugated paper board and a valley of the corrugated inner memment with the axis of the' barrel 1. Above the base of the block 2 is'arranged a knurled lock nut 3 screwed tightly down upon the block so that both the block and nut are immovably secured to the barrel. Slidably :md rotatably engaging the upper end of the barrel is arranged a lmurled operating sleeve 4, withinwhich is rigidly secured, in

l ber thereof. This finger is orificed in alinethe present instance by means of the oon-- necting screw 5,'a depending tubular screw 6 engaging the internally threaded upper The lower end of the screw 6 is formed with an internal annular shoulder 6a' arranged to coperate with a nut 7 carried by the screw-threaded upper end of the'stem 8 of the plunger member.

The plunger stem has a loose sliding fit within the annular shoulder 6, and the nut 7 fits loosely within the bore of the screw 6.- The lower end of the plunger member consists of a head 8" slidably engaging the bore of the barrel of the tool and equipped with a plunger point 9, which in the present instance, as shown, is made removable and 'is secured to the plunger head by means of a set screw 9a the head of which slidably en gages a slot in the barrel, whereby rotation of theplunger member is prevented. Between the plunger head 8"L and a bearing face at the lower shouldered end of the screw 6, and surrounding the plunger stem 8 within the barrel of the tool, is arranged a helical spring 10, an anti-friction bearing consisting of a washer 14 and a set of balls 15 being provided intermediate the top of the spring and the bearing face of the screw for the purpose of practically eliminating friction at that point. An adjustable stop ring 11 is provided which may be set at any desired indication of a graduated scale 12 formed on the barrel 1, and seated within an internal annular groove in such ring is arranged a C-shaped friction ring 16 which corresponding to those afforded by testing machines already well known in the art and nominally (though not in all cases accurately) indicating in pounds per square inch l the pressure required to puncture or burst through a sheet -of paper. 1t will be understood thatv the usual and recognized method of making a bursting test is to apply pressure gradually to a restricted area (through an elastic diaphragm expanding through an opening, or by means of a plunger) until the paper reaches the limit of its strength and,

suddenly ruptures, this strength being indicated upon a scale-nominally indicating square inch.

the stress upon the paper in pounds per With the construction and arrangement of parts described it is obvious that the finger 2a of the tool being inserted in a piece of corrugated board between the top facing and corrugated member, and the knurled sleeve 4 being rotatedv to screw the Dconnected screw 6 down against the spring 10, the plunger point will be carried down until it bears upon the-top facing of the board and then subjected tol increasing stress of the spring until the paper bursts, 4unless downward movement of the sleeve is interrupted by its lower end bringing up against the stop ring 11 before a rupture occurs. The downward movement of the connected sleeve and screw, and consequently the compression of the spring, is indicated by the movement. of the lower edge of the sleeve 4 over the' graduated scale 12. The stop ring may therefore be set to the graduation indicating the mini-r mum strength required of the particular facing, and unless the paper bursts before contacting the stop it of course meets the requireinent satisfactorily. inner facings may be thus tested separately to determine whether they satisfy any required specification of strength.

The outer and.

If it be desired to ascertain the exact I bursting strength of the facings, instead of whether' they pass a test of required minimum strength, the ring 11 should be shifted upwardly intocontact with the lower edge of the sleeve and the sleeve rotated slowly until a break occurs, the ring being forced downwardly by the sleeve. The sleeve being now rotated in the reverse'direction to enable the device to be disengaged, the stop ring-will' be retained through the action of the friction ring 11' at the point at which it was left when the break occurred, and the bursting strength will be indicated upon the scale 12. The two facings may be thus tested separately, and their `combined values will,

be the total or combined bursting strength of the board. It is obvious that if desired the stop ring can be shifted to eXtreme downward position, and by rotating the operating sleeve slowly until a break occurs, stopping the movement immediately at this point, the edge of the sleeve will indicate upon the scalevthe bursting strength ofthe paper.

Vhile in Figs. 1 to 4 inclusive I have illustrated a form of plunger tool having a circular face slightly cupped at the center and with a rounded edge, this form `being well adapted to give the general or average value of' a facing sheet, yet for the purpose of providing for more accurate tests of the relative strength of paper measured with the grain,-that is, machine-ways of the paper, and across the grain, I have provided the form of plunger point shown in Figs. 5, 6 and l7 in which the Working face consists of parallel blunt ridges 14a. With this tool A or point arranged so that its ridges lie with thc grain in the general direction of most of the fibers (in case of paper having a pronounced grain) the ridges will divide and separate groups of longitudinal bers without initially breaking them, and the stress will be borne by the transverse fibers which 'will break initiatingv a burst of the plunger through the paper and giving an indication of the strength of the paper across the grain. When the plunger point is arranged so lthat the ridges lie transversely of the iio grain the longitudinal fibers will sustain l the stress and at the point of lrupture the strength of the paper with the grain will be indicated. The faces of the round plunger point shown in Figs. 1 to 4 and that of the form last described are such that they will give the same vindications upon perfectly matted or felted paper having no appreciable grain, and it has been found that upon papers having a marked grain the indications of the round faced plunger is intermediate that of indications taken with ridged plunger with and across the grain. The last mentioned, form of plunger may also be made to give an average or interme- `thereto diate indication by setting it to position approximately half Way between those above described.

From the description above given it is obvious that my novel device may be conveniently used to test boxes made up and packed for shipment, either at a point Where anexposed edge of the material is presented or by making a small incision (not injuring the package materially) to enable the finger of the tool to be applied. It is also manifest.

1. A testing device of the character de-Q scribed and comprising a shank, an orificed finger secured to said shank adjacent one end thereof and arranged at right angles thereto, a plunger member slidingl mounted in said shank and equipped Wit a plunger point in alinement With the orifice in said finger, a coiled' spring arranged to bear at one end against said plunger member, and a manually operable member arranged to coperate with the other end of said spring to yieldingly force said plunger member toward said finger, said shank and said manually operable member being one or the other marked With a graduated scale to indicate their relative movement.

2. A testing device of the character described and comprising a hollow shank, an orice'd finger secured to said shank adjacent one end thereof and arranged at right angles thereto, a plunger member slidingly mounted Within said shank and equipped .with a plunger point in alinement with the orifice in said finger, a coiled spring arranged to bear at one end against. said plunger member, and a longitudinally movable sle'eve surroundin said shank and arranged to coperate with the other end of said spring to yieldingly press said plunger member toward said finger, said shank and sleeve being one or the other provided With a graduated scale to indicate their relative movement.

3. A'testing device of the character described and comprising a tubular shank, an

orificed finger secured to said shank adjacent one end thereof and arranged at right angles stem extending axially thereof, said plunger I with a plunger 4member and said sleeve,

I a plunger member having a head p slidingly mounted Within said shank and a member being equipped with a plunger point in alinement with the orifice in said linger, a coiled compression spring surrounding the stem and bearing at one end against the head of said plunger member, a longitudinally movable sleeve surrounding said shank and arranged to cooperate With the other end of the spring to yieldingly press the plunger member toward said finger, said shank and sleeve being one or the other provided With a graduated scale to indicate their relative movement.

4. A testing device according to claim 3 in which the end of the shank and the sleeve are connected by screw-threaded engagement. v

5. A testing device threaded and said sleeve is slidable and rotatable upon the outer surface of the shank and is provided With a depending externally' ythreaded element engaging the threaded end of the shank.

6. A testing device yof the character described and comprising a tubular shank, an orificed finger secured to said shank adjacent one end thereof and arranged at right angles thereto, a. plunger member slidingly mounted Within said shank and equipped point in alinement with the orifice in said finge/'na sleeve connected by screw-threaded engagement With said shank, and a spring intermediate said plunger s'aid shank being marked with a graduated scale coperating with the end of the sleeve to indicate their relative movement.

7. A testing device of the character described and comprising a tubular shank, an orificed finger secured to said shank adjacent one end thereof and arranged at right angles thereto, a plunger member slidingly mounted VWithin said shank and equipped with a plunger point in alinement with the orifice in said finger, a sleeve connected by y screw-threaded engagement With said shank,

a spring intermediate said plunger member and said sleeve, said shank being marked with a graduated scale cooperating with the end of the sleeve to indicate their relative movement, and an .adjustable stop on said shank arranged to be set at any desired graduation of the scale.

8. A testing device according to claim 7 in Which the stop isa sliding ring surrounding'the shank and equipped With a setscrew..

' JOHN W. WEBB.

according to claim 3 lin which the end of the shank is internally 

